For some mysterious reason its not possible to upload a file to a profile in Fuse 6.1. Since we tend to script the complete creation and deployment of our Fuse environments we needed to be able to add files to profiles from a script.

The support guys gave me this script that adds a function called ‘import-resource’, and since it really helped us I though I’d share it with the internet:

Running the Camel-Tinkerforge component is really easy on Karaf. The ready to go feature files make installation easy, and the use of the auto-deployment directory makes testing different route configurations also easy.

The camel-tinkerforge component is part of the Camel-labs IoT project. We just got started with this so the first release is still pending. This means you need to checkout the code from https://github.com/camel-labs/camel-labs and run “mvn install -DskipTests=true”. There’s no need to run the tests since the buildserver has already done that. :)

To intall Camel-Tinkerforge on Karaf 2.x run the following commands in the Shell:

Run log:tail in the karaf Shell and copy the xml file to the deploy directory in the karaf installation directory. Notice how Karaf starts the camel routes defined in the xml file, and writes messages to the log whenever the temperature changes.

Now you can start experimenting with different routes in the xml file, and as soon as you save the file Karaf will automatically reload the routes.

When you create a container in fabric you can specify which options should be passed to the container. This way you can set the amount of memory for instance, but you can also specify that the container should start in debug modus.

The following Fuse CLI command would create a container with a maximum heap size of 256 MB:

container-create-child --jvm-opts "-Xmx256m" root child

In the Hawt.io console you’ll find the “Jvm opts” option under the “Advanced” tab on the container creation page.

Now you can also use this to pass the regular debug commands to a JVM: “-Xdebug -Xrunjdwp:transport=dt_socket,address=5001,server=y,suspend=n”.

The suspend=n part means that the JVM won’t wait for a debugger to connect but will startup like usual. If you need to see what happens in the JVM right after it starts you can change this to suspend=y. The JVM will then block until a debugger is connected.

I noticed the (optional) fan on my Odroid U3 frequently spinning up only to shut down again 1 second later. This appeared rather buggy to me so I looked into how to control the fan. This is what I found:

Note: The ‘odroidu2′ part of the path is not a typo! Strangely enough the U3 uses the same device path as the U2.

Once you’ve switched the fan into manual mode, you can set the speed of the fan by echo-ing a value between 0 (0%) to 255 (100%) to the fan controller:
echo 0 > /sys/devices/platform/odroidu2-fan/pwm_duty (fan off)
echo 255 > /sys/devices/platform/odroidu2-fan/pwm_duty (fan on full speed)

Fun fact: You can get into an argument with the automatic fan controller by setting the fan speed while in auto mode. The fan will respond to your command but the automatic controller will shut it down after noticing what you did. :)

While playing with the fan use the following command to read the CPU temperature:
cat /sys/devices/virtual/thermal/thermal_zone0/temp

And to run a CPU stress-test that utilizes all 4 cores use this command:
sudo openssl speed -multi 4

Update:
If you have the latest version of the kernel it gets even simpler. You can set the temperature above which the fan should be used to cool down the SoC:
echo 60 > /sys/bus/platform/devices/odroidu2-fan/start_temp

After installing Netbeans and Java7 for some JavaFX tinkering several of my other apps stopped working.

A lot of the solutions I found online involve writing scripts or changing startup scripts for specific programs, but I found none of them easy or maintainable enough. I ended up altering the symbolic link named “Current” in /System/Library/Frameworks/JavaVM.framework/Versions

A link called CurrentJDK in the same directory still pointed at a 1.6 version, so I simply changed the Current link to point to the CurrentJDK link. That way I can simply change it back when I want 1.7 to be the default.

Today a colleague needed help with setting up a Glassfish cluster and I remembered having read a very good tutorial that created the entire cluster using only asadmin commands. In my experience using only asadmin commands not only gives you a greater understanding of the way Glassfish works internally but also enables you to create scripts for Glassfish administration commands.